Apparatus for collecting fluid samples



W 1947- E. J. GRACE, JR 2,418,876

APPARATUS FOR COLLECTING FLUID SAMPLES Filed Oct. 6, 1944 Fatented Apr.35, 194? APPARATUS FGR COLLECTING mum SAMPLES Application October 6,1944, Serial No. 557,497

filaims.

i The present invention relates to an apparatus IF; s

i: gaseous phase for the purpose of subsequently analyzing the collectedsamples.

The commercial production of many gases and liquids varies in accordancewith operating conditions and at one period they may be manufactured ata comparatively rapid rate and at another period at a much slower rate.Likewise the quality of the fluids produced will vary greatly duringdifferent periods of their manufacture. It will be appreciatedtherefore, ,that a sample of a s or liquid taken atone stepor stage oiits manufacture would not be truly representative of either the quantityor quality throughout the entire period of production or flow of suchgas or liquid, from the source at which it is bein manufactured. At oneperiod of its manufacture it may be very rich, at another period verylean; at another period or step, its rate of manufacture may be veryfast and at another step of its manufacture very slow.

By my invention I can obtain a sample which will show the true qualityof the product being manufactured since the volume of the sampleobtained will have a direct relation to the total volume of fluid passedthrough the line during the sampling period. This relation will bemaintained regardless of varying flow conditions of fluid through theline.

An object of the present invention is to provide 7 for the collection ofa representative sample of fluid flowing through a line over a period oftime.

A further object of the present invention is to provide a device orsystem for collecting a sample in accordance with the volume of fluidpassed through a line.

Other objects of the invention will become apparent as the descriptionproceeds.

In the drawings: v

Fig. 1 i generally a diagrammatic elevational view with some partssectioned to show details.

' Fig. 2 is a view on the line 2-2 of Fig, 1.

Referring to Fig. 1, it represents the main conduit through which theliquid or gaseous medium flows and adjacent the right end of the conduitis the branch line H through which the sample fluid is collected.Adjacent the opposite end of the conduit portions of a conventional flowrecorder of the pressure compensated inte grator type are shown. Thesecomprise a manometer l2 which actuates diiierential pressure arm l3 inaccordance with the dillerential pressure across an orifice plate in theconduit and a Bourdon tube it which actuates static pressure arm iii inaccordance with the static pressure existing in the conduit. Identicaldrums l8 and ii cooperate with arms l3 and I5 respectively and each isprovided with a cylindrical raised surface which increases in width fromright to left in proportion to the reading on a square root scale shownpositioned in front of each drum. Drum It is driven by motor l8 to makeone rotation during a set period, for example, each minute, andthroughout the interval in which the differential arm 13 rides on theraised surface of drum I6 the rocker lever l9 on which the scale ismounted will be forced outwardly by the differential arm l3 to eilect anengagement of the gears in gear trains 20 and 2| causing rotation ofstatic pressure drum IT. The degree that the static pressure drum ii isrotated by a full revolution of the differential pressure drum It willdepend on the width of the raised surface at the point where thedifferential pressure arm l3 momentarily rests. Similarly, throughoutthe interval in which the static pressure arm I5 rides the raisedsurface of the static pressure drum l'l, its rocker lever 22 will effectan engagement of the gears in gear trains 23 and 24 (a will be seen fromFig. 2) to raise rocker arm 25 through linkage 2t.

The branch line H through which the sample fluid is collected isprovided with valve means generally indicated at 30 which is arranged toremove fluid from conduit ID in response to the movement of the controlrocker arm 25 for collection in vessel 3 I. The valve means mayconveniently take the form of a three-way valve plug indicated at 32,the movement of which is controlled, for example; through a constantspeed motor 33-, a series of switche M, 35, 36, motor shaft 31, andconnecting rods 38 and 39, to periodically place the valve incommunication with the collecting vessel 3i and a cooperating measuringvessel til. I

In operation, the rocker arm 25 is actuated in accordance with thevolume of fluid which has passed through conduit [0 by means of drum I!of the flow meter and themercury switch 34 will be tilted to the rightfrom the position shown and remain in this position until the linkage 26drops to reverse the movement of arm 25 and again open switch 34. Thusthe circuit to motor switch 36 is opened. The passageway ll in valveplug 32 will be assumed to be in the position valve plug 90 motor 33 itsshaft 31 will make one-halt revolution and through connectingrod 38 willrock the until its passageway 4| is in communication with branch line Hand line 42 to place collecting vessel 3! and measuring vessel 40 incommunication until the valve plug 32 is again moved under the actuationof rocker arm 25. When the valve plug 32 has been rotated 90, mercuryswitch 35 will be tilted, irom its shown position, to the left throughrod 39 breaking the circuit to motor 33 and the movement of valve plug32 will be stopped. The valve will remain in this position until it isagain actuated in accordance with the volume of the fluid passed throughline I. The valve 32 will be actuated at variable time intervals whichare determined by successive equal volumes of fluid passed through lineH! and it is obvious that the motor actuating valve 32 will at all ofits energizations effect the actuation to transmit and discharge thedisplacement liquid within equal time intervals.

In order to adapt the apparatus tor the collection of gas, vapor, orliquid, the vessel 3| will first be filled with a displacement liquidsuch as ethylene-glycol and as long as vessels 3| and 40 are incommunication a portion of the displacement liquid in vessel 3| will betransferred to vessel 40 and the sample fluid from conduit I will becollected in vessel 3| in a volume equal to the liquid displaced. Whenthe valve plug 32 is again moved in accordance with the volume of thefluid passed through conduit II), the passageway will be placed incommunication with line 42 and disposal line 43 and the displaced liquidwhich had entered vessel 40 will be discharged into a suitable container44. The operation of the apparatus will continue until all thedisplacement liquid is removed from the vessel 3| and it is completelyfilled with the sample medium from conduit ill at which time the vessel44 will contain the displacement liquid which was originally incollection vessel 3|. At this point in the operation, the vessel 44 isarranged to stop the operation of the collecting apparatus and to thisend switch 36 will be moved from its shown closed position through arm45 under the weight of the liquid in container 44 and the circuit tomotor 33 will be broken. In order to prevent escape of collected gas orvapor back into main conduit ID a pressure reducing valve 46 ispositioned between the line l0 and the collecting vessel 3| which willbe set to hold a constant pressure lower than any pressure in the mainline.

When the control arm 25 'is actuated in accordance with the volume ofthe fluid passed through the conduit Hi the switch 34 will be actuatedto closed position and will remain in this position for a length of timedepending upon the volume of the fluid passed through conduit I0. Hencepassageway of valve 32 will place collecting vessel 3| and measuringvessel 40 in communication for the length of time during which theswitch 35 remains closed. The vessel 40 is designed to receive only a,measured amount of displacement liquid from vessel 3| regardless of thelength of time that the vessels are in communication. The relative sizeof the measuring vessel 40 to that of the collecting vessel 3| will'tional portion of liquid from vessel 3| each time that the valve 32places the vessels in communication. Since the pressure in line in mayvary over any period of operation the-volume of vessel 40 will be basedon an anticipated or estimated volume to be passed through line l3 inorder that the liquid originally in vessel 3| will be entirely removedtherefrom and replaced by the sample fluid from line H]. In practicaloperation of the collecting apparatus the vessel 3| will probably becompletely emptied of the displacement liquid before the selected periodof time has elapsed for collecting the sample and to overcome thispractical difficulty in utilizing the invention a chart 41 is controlledby the operation of motor l8 and consequently, when the vessel 3| isfllled with the collected sample and the displacement liquid originallyin vessel 3| has been transferred to container 44 and the emergencyswitch 33 has been open to stop operation of motor 33, the movement ofthe chart 49 will likewise be stopped and from the chart the actualperiod for the collection of fluid in vessel 3| can be noted theredependon the volume of sample it is desired to collect over any definiteperiod. For example, if it is desired to collect a gallon of samplefluid in vessel 3| over a twenty-four hour period. vessel 40 would bedesigned to receive only a fracp, IO

from. c.

In order to readily adapt the vessel 40 for varying volumes of fluidpassed through line H! the vessel will take the form of a hydron orbellows arrangement so that the volume of the vessel may be variedexpeditiously through the spring 41 and adjusting screw 48. Through thisadjusting means the volume of vessel 40 when it is in expanded conditioncan be set to receive a volume of liquid from vessel 3| estimated on theexpected average rate of flow through line H! and when it has receivedthis volume of fluid it will be retained therein until the valve 32 isagain actuated to place the vessel in communication with the container44 and throughthe force exerted by spring 41 the hydron or bellows willbe collapsed to expel the fluid trapped therein.

While certain novel features of the invention have been shown anddescribed it will be understood that the invention contemplates variouschanges in illustrated device and is to be limited only by the scope ofthe appended claims.

I claim:

1. Apparatus for obtaining an average sample from a streamof fluidflowing through a conduit which comprises a branch line in communicationwith the conduit, a collecting vessel in said branch line containing adisplacement liquid, valve means for removing the displacement liquidfrom said vessel to permit the sample fluid to be collected therein, ameasuring vessel for receiving predetermined volumes of liquid from saidcollecting vessel, a flow meter operated in accordance with the volumeof fluid passed through said conduit, switch means controlled by saidflowgmetcr for actuating said valve to transmit a predetermined volumeof displacement liquid to the measuring vessel, said flow meter beingoperative to discharge each volume of liquid from the measuring vesselto a reservoir, and means operative when the reservoir has received thevolume of liquid originally in the collecting vessel for stopping thesample collecting operation.

2. Apparatus for obtaining an average sample from a stream of fluidflowing through a conduit which comprises a branch line in communicationwith the conduit, a collecting vessel in said branch line containing adisplacement liquid, valve means for removing the displacement liquidfrom said vessel to permit the sample fluid to becollccted therein, ameasuring vessel for rell'n A ,3

- be collected therein,

ceiving predetermined volumes of liquid from said collecting vessel,means operative at variable time intervals determined by successiveequal volumes of fluid passed through said conduit for actuating saidvalve means to transmit the predetermined volume of displacement liquidto the measuring vessel and to discharge each volume.

of liquid-from the measuring vessel.

3. Apparatus for obtaining an average sample from a stream of fluidflowing through a conduit which comprises a branch =-line incommunication with the conduit, 3. collecting vessel in said branch linecontaining a displacement liquid, valve means for removing thedisplacement liquid from said vessel to permit the sample fluid to abellows type measuring vessel of adjustable capacity for receiving pre,determined volumes of liquid from said collecting vessel, meansoperative at variable time intervals determinedby successive equalvolumes of fluid passed through said conduit for actuating said valvemeans to transmit the predetermined volume of displacement liquid to themeasuring vessel and to discharge each volume of liquid from themeasuring vessel.

4. Apparatus for obtaining an average sample from a stream of fluidflowing through a conduit which comprises a branch line in communicationwith the conduit, 9. collecting vessel in said branch line containing adisplacement liquid, valve means for removing the displacement liquidfrom said vessel to permit the sample fluid to be collected therein, acollapsible measuring vessel for receiving predetermined volumes ofliquid from said collecting vessel, flow controlled means operative atvariable time intervals determined by successive equal volumes or fluidpassed through said conduit for actuating said valve branch linecontaining a displacement liquid,

-valve means for removing the displacement liquid from said vessel topermit the sample fluid-to be collected therein, a measuring vessel forreceiving predetermined volumes of liquid from said collecting vessel,means operative at variable time intervals determined by successiveequal volumes of fluid passed through said conduit for actuating saidvalve means to transmit the predetermined volume of displacement liquidto the measuring vessel and to discharge each volume of liquid from themeasuring vessel, said valve-actuating means including a motor adapted,at each actuation of the valve means, to efleet its liquid transmittingand discharging operation within the same time interval.

. EDWARD J. GRACE, JR.

- assurances err-an The following references are of record in the die ofthis patent:

UNITED STATES PATENTS

